A drive circuit such as this known from the prior art is shown schematically in FIG. 1. The so-called intermediate circuit voltage UZW is applied on the input side. In this case, the intermediate circuit voltage UZW is a DC voltage which is usually generated from the system voltage using circuits which are familiar to those skilled in the art. Two switches S1, S2 are arranged in series in a half-bridge arrangement and are driven by a respective input circuit E1, E2 (not shown). The connecting point of the two switches is connected, via an inductor L, to the lamp La, through which the lamp current IL flows during operation. On the output side, the two coupling capacitors CK1, CK2 terminate the circuit. Alternative circuit structures are familiar to those skilled in the art, but are not described in any more detail below since they are irrelevant to the implementation of the invention. In the case of use in the so-called medium-voltage range, the switches S1, S2 must be designed for connecting voltages of between 400 and 1000 volts. The switching frequency is of the order of magnitude of from 40 to 50 kHz. The duty cycle of the circuit shown in FIG. 1 is 50 percent. The system supply power to be connected is in this case more than 100 watts. In order, furthermore, to make it possible for the system to be controlled in a relatively simple manner using microcontrollers or integrated control modules, at present MOSFETs (metal oxide semiconductor field-effect transistors) and IGBTs (insulated gate bipolar transistors) are used as the switches. Since, in the case of field-effect transistors, the forward power losses increase with the square of the current, and the chip area needs to be correlated with the forward power losses, MOSFETs are relatively expensive in the case of currents above one ampere and medium voltages of approximately 600 volts. In the case of IGBTs, on the other hand, high forward power losses result. In the case of simple bipolar transistors, in which the forward power losses are directly proportional to the current, components designed for such boundary conditions are less expensive, since they require less chip area. However, their poor dynamic switching behavior has a negative effect. Since the collector current cannot be disconnected quickly enough, the temporal overlaps with the collector-emitter voltage result in high switching losses.